Traditional IP network performance monitoring uses a solution based on active measurement. The solution of active measurement is a test solution in an analog form, and a test packet is exchanged between node A and node B in a network to determine performance such as packet loss, a delay, and a jitter on a network path between node A and node B. Testing a delay is used as an example. Node A generates and sends a test packet to node B every a predetermined period, and node A records a sending time T1 of the test packet. After receiving the test packet, node B constructs a test packet that is to be used as a response packet, and sends the response packet to node A. After receiving the response packet, node A records a time T4 at which the response packet is received. A difference between T4 and T1 is calculated to obtain a round-trip delay between node A and node B. The solution of active measurement increases network load.